Developing load data for .40 S&W

[ShaulWolf]

I'm trying to develop load data for an upcoming batch of ammo under the tutelage of a friend. I thought it would be a good idea to get some more knowledge and see what I could learn before going to the reloading bench. That and I'm pretty sure he's asleep since I work midnights. :P

Background data:

• I'm going to be loading two different bullet weights: 125 gr Sinterfire for target and competition shooting, and 165 gr Gold Dots for self defense.
  
• I'll be firing these from my M&P40 full sized, which has a 4.25" barrel and fully supported chamber.
  
• I'll be using CCI small pistol primers.
  
• I'll likely be loading the bullets a little long.
  
• I want to maximize velocity while trying to keep recoil and muzzle flash down if possible. Preference goes to keeping velocity high to push for maximum expansion and terminal performance. If possible, I'd like to try to keep the recoil on the 125 gr rounds similar to the 165 gr rounds, though I know the difference in bullet weight will have quite an impact on the felt recoil. Even so, I'm trying to get a little more snap out of the 125s.

I've looked over Hodgdon's website and found the following:

• Hodgdon Universal powder will push 125 gr bullets 1058-1172 fps, and 165 gr bullets 976-1061 fps.
  
• Hodgdon Titegroup powder will push 125 gr bullets 1041-1145 fps, and 165 gr bullets 961-1047 fps.
  
• Hodgon Longshot powder will push 165 gr bullets 1139-1185 fps, but no data is shown on the Hodgdon website for 125 gr bullets.
  
• IMR SR 4756 powder will push 165 gr bullets 1075-1168 fps, but no dada is shown on the Hodgdon website for 125 gr bullets.

Burn rates, from fastest to slowest, with their ranking on Hodgdgon's burn chart are:

• Titegroup (14)
• Universal (32)
• 4756 (39)
• Longshot (52)

Questions:

• How will the burn rates affect ballistic and terminal performance of the rounds?
  
• How much variance in velocity will the differing burn rates give out of the 4.25" barrel?
  
• What are the characteristics of the different powders mentioned? As in muzzle flash, felt recoil, etc.
  
• Does the lack of data for 125 gr bullets show that those particular powders would be unsafe to use?

Thank you.

[ShaulWolf]

Ok, some helpful knowledge handed down.

Faster powders reach max pressure faster and will create more speed from a short barrel than a slower powder.However, a slower powder will make more speed if given enough barrel length. If the barrel is too short you will still have unburnt powder when the bullet leaves the barrel, which will create more muzzle flash.

So the trick here would be using a powder that burns just right in a 4.25" barrel since I can tweak the amount of powder either way to push the bullets out past 1000 fps.

[ShaulWolf]

Damn, so our supplier for Sinterfire bullets isn't an option now, and may not be for some time. Switching to Mastercast this time around.

• Going to split a case of 165 gr. TMJ flat points, so recoil should be the same as the carry ammo I'm going to load.
• I'm looking at either Hodgdon's Universal or HS-6 powder, preference leaning towards HS-6.
• I'll be stopping by the local gun shop to check out primers, with no real preference towards primers.
• Got brass to be tumbled already, so good to go there.

The journey continues.